William Stanley Jr. was an American inventor born on February 2, 1858, in Brookfield, Massachusetts. He is best known for his work in electrical engineering, particularly for developing the first practical transformer, which significantly improved the efficiency of electrical power transmission. His innovations laid the groundwork for modern electrical systems. Stanley also contributed to the development of the AC (alternating current) system, which is widely used today. He founded the Stanley Electric Company and held numerous patents throughout his career. His work has had a lasting impact on the field of electricity and power distribution.